Research will be continued on the mode of action of procarbazine using L-5178Y murine lymphoma cells both in vivo and in tissue culture. Major emphasis is upon the role of glutathione and other thiols in the cellular effects of procarbazine. Various thiol reagents, e.g. diethyl maleate, diamide, and N-ethyl maleimide are being employed with procarbazine to assess the combined effects upon energy metabolism, protein synthesis and transplantability. Reduced and oxidized glutathione levels are measured during the course of the various experiments.